Table 1 Summary of the previous studies examining the effects of heating on the SIgA concentrations and lysozyme activity
Ref | Year | Sample (n) | Current LabCorp Method | Intervention | Effects | ||
|---|---|---|---|---|---|---|---|
SIgA | Lysozyme | IgA | Lysozyme | ||||
Paulaviciene et al. [23] | 2020 | 42 | NS | ELISA using the commercial CircuLex Human Lysozyme ELISA Kit (MBL, Japan) | Comparison of the effects of HoP (62.5 °C for 30 min) with fresh HM | NS | Reduced (p = 0.007) |
Vieco et al. [22] | 2018 | Multiple donors from a human milk bank | Duplicate results obtained using a Bio-Plex 200 system instrument (Bio–Rad Hercules, CA, USA) and determined with the Bio-Plex Pro Human Isotyping Assay (Bio–Rad Hercules, CA, USA) | NS | Comparison of the effects of HTST treatments at different temperatures (70, 72, or 75 °C) for different times (5, 10, 15, 20, and 25 s) with HoP, (62.5 °C for 30 min) | Greater IgA retention was observed after any of the HTST treatments than after HoP (p < 0.001) | NS |
Chang et al. [21] | 2013 | 16 | SIgA ELISA kit (K8870; Immundiagnostik AG, Bensheim, Germany) | Lysozyme enzyme immunoassay kit (Biomedical Technologies Inc., Stoughton, MA, USA) | Comparison of the effects of warming at 40 °C with warming at 60 °C | Stable | Stable |
Handa et al. [24] | 2014 | 40 | SIgA ELISA kit (ALPCO Diagnostics, Salem, NH, USA) | NS | Comparison of the effects of heating between samples thawed at 4 °C for 24 h prior to warming and those immediately thawed and warmed at 37 °C after being removed from the freezer (-20 °C) | Stable | NS |
Akinbi et al. [20] | 2010 | 18 (fresh) 15 (pooled specimens of pasteurized milk) | Enzyme-linked immunosorbent assay (ALPACO Diagnostics, Salem, NH) | Anti-human lysozyme (Accurate Chemical and Scientific Corp, New York, NY, USA) | Comparison of the effects of pasteurization (pulse heating at 62.5 °C for 30 min) with fresh HM | Reduced (p < 0.0001) | Reduced (p < 0.001) |
Evans et al. [13] | 1978 | 6 (IgA samples) 9 (Lysozyme samples) | Electroimmunoassay | Electroimmunoassay | Assessment of the effects of pasteurization for 30 min at 60, 62.5, 65, 67.5, and 70 °C | Progressive loss of SIgA with increases in the heating temperature | Progressive loss of lysozyme activity with increases in the heating temperature |